Ok I know somebody had a graph of penis volume a couple days ago, and being the math guy that I am I decided to take the idea and run with it.

Here is a graph that tells you where you stand. Please allow me to explain it:

CALCULATIONS

OK, when dealing with a penis with two variables, length (L) and circumference (C), you need to get a little more in depth than calculating the volume of a cylinder. The penis has a round end so for this calculation we will be adding a half sphere to a shortened cylinder.

The sphere - the volume of a sphere is 4/3(pi)r^3 where r is the radius of a circle with a circumference of (C).
Since
C=2(pi)r,
r=C/(2pi).
Now our sphere formula is
4/3(pi)(C/(2pi))^3.
Since we only need the volume for half of this the formula becomes
2/3(pi)(C/(2pi))^3
Simplify:
(C^3)/(12(pi)^2)

The cylinder - the volume of a cylinder is (l)(pi)r^2 where (l) is the length of the cylinder. (l) in our case is actually (L)-r because we have to account for the tip. Remember r=C/(2pi), so we have a volume of
((L) - C/(2pi))(pi)(C/(2pi))^2.
Simplify:
(L - C/(2pi))((C^2)/(4pi))

So the total volume of your penis is

V = (C^3)/(12(pi)^2) + (L-C/(2pi))((C^2/4pi))

HOW TO DETERMINE YOUR "REAL" VOLUME

First of all this chart assumes that you have a straight penis, and that the circumference is the same throughout, so you cone shapes and mushroom shapes may need to come up with an "average" circumference to get an accurate measurement. Hook shaped curved guys need to curve their measuring tape. Also, you guys should measure properly and report honestly. For length, measure with a straight tape on the TOP from your pubic bone to the end. For girth, lay the one end of the tape on it's end and wrap it snuggly and read the measurement where the end of the tape sits.

Results:

Lets start at the dotted line since I have determined this line to be the worldwide average for volume.

GREEN - Congratulations, you are considered above average!! If you are in this region you should never have anything to worry about. Personally, I am in this zone right in the middle between the dotted line and the BLUE region, and I have always gotten rave reviews for my schlong.

BLUE - OK if you are in this region, I would guess you are in the top 3-5% of guys, and as such you should consider being an exibitionist at the next big party. You'll have girls knocking down your door.

PURPLE - If you are in this region, allow me to shake your hand. I hope I don't offend anyone by saying this but most of you guys will claim to be in this region but most of you are not. This region probably represents the top 0.5-1% if you measure CORRECTLY and report ACCURATELY. Some of you look like you are in this region, and for that my hat is off to you guys. As far as porn stars are concerned, I would say that Sledgehammer, Billy Glide, Julian, Mr Biggz and others like them would fit this category.

WHITE - If you made this category allow me to bow down to your greatness, then slap you silly for not making hardcore porn movies! This category is reserved for an extremely small, select group of individuals in this world. Believe it or not, there are a couple of LPSG members that make this category. Wrist_Thick is one of them, lol. Pornstars that I think make this region are Shane Diesel, Mandingo, Jack Napier, and maybe Shorty Mac. For those people that will scream at me that they are in this group allow me to put this group into perspective and I will allow you to prove me wrong - A 20 oz Gatorade bottle is 8X9 and contains 37 ci of fluid. Please prove me wrong by taking a photo of your penis next to one.

YELLOW - Hey don't feel bad! If you are in this category you probably haven't gotten many complaints as long as you know how to work it. Many in this category probably have gotten complimented on their size. And if you are a 7X4 'shower' you probably are considered pretty huge. But in the end, your region is yellow for a reason. Be cautious when making the decision to whip it out at the next party.

ORANGE - I would call this the danger zone because some people in this region might think they are well hung (like for example 6X4 would probably be considered an average size) but lets not lose sight of the fact that VOLUME wise, this is considered relatively small.

RED - This would be considered very small and in some cases, you may want to consider seeing a doctor about some type of medical procedure. Maybe you are ok if you are one of those 6X3 guys, but you might want to make it a point to never bring it out in public unless you are a major "shower".

Thank you for posting this chart. It does a great job of illustrating something I'd conceptualized (but didn't do the math to make a real comparison) -- that a relatively "small" difference in length and girth results in a significant difference in volume.

For example, my lover's cock is about 15% larger in both dimensions (length and circumference) than my ex's, but in volume, it is approximately 40% larger, according to the chart.

The math checks out, except many glanses aren't hemispherical. Since we're being super geeky here, I'll say many of them are shaped more like the helmets that the Death Star technicians wear. BUT the glans accounts for a small proportion of the overall volume (mine was about 10%, for example) that it's not usually enough to make a difference to where you are on the chart.

Anyway, this seems to line up with the most objective length/girth charts I've seen. While not much above average in length I seem to be much thicker than average (say, 80th percentile), so I get well into the blue area on the chart, and I get the compliments (but not the intimidation) to prove it. Girth makes all the difference here, as it does in sex.

Something else interesting (to a math geek such as myself) is the seemingly huge range of volumes encompassed. Consider that an "average" penis is 11 ci on the chart, while my blue boy falls around 17.7 ci -- that makes me 60% bigger than average, by volume. Nice! But a 9" x 7 " penis is a hefty 33 ci (give or take), 85% bigger than me, and 300% the size of "average." Zoinks! No wonder they get scared.

For an education on the wide range of bodies and body parts available to we humans, check out the difference in volume between B-cup and E-cup breasts on a woman with a 36" chest. It's similar to the difference between the 9x7" porn star and the 6x5" average Joe. And if you look at the percentage of women who wear an E-cup bra you'll find it's similar to the percentage of men with a 33ci penis. It all fits in a bell curve. Cool!

A hemisphere on a cylinder. Still not much of a model. How about just measuring it directly?

Good idea. Just fill a pot to the brim with water, set it in a bigger pan, get a big-ole erection and do one pushup into the water. Do a one-handed push-up and keep your balls out of the water. (My advice is to use warm water, but not TOO warm! This is getting more and more difficult...) Pour the water that overflows into the pan into a finely graduated measuring cup and get the volume that way. 1 oz of water = 1.8 cubic inches.

Not the easiest thing to do, but it's a good way to check the correctness of the model.

The math checks out, except many glanses aren't hemispherical. Since we're being super geeky here, I'll say many of them are shaped more like the helmets that the Death Star technicians wear. BUT the glans accounts for a small proportion of the overall volume (mine was about 10%, for example) that it's not usually enough to make a difference to where you are on the chart.

Anyway, this seems to line up with the most objective length/girth charts I've seen. While not much above average in length I seem to be much thicker than average (say, 80th percentile), so I get well into the blue area on the chart, and I get the compliments (but not the intimidation) to prove it. Girth makes all the difference here, as it does in sex.

Something else interesting (to a math geek such as myself) is the seemingly huge range of volumes encompassed. Consider that an "average" penis is 11 ci on the chart, while my blue boy falls around 17.7 ci -- that makes me 60% bigger than average, by volume. Nice! But a 9" x 7 " penis is a hefty 33 ci (give or take), 85% bigger than me, and 300% the size of "average." Zoinks! No wonder they get scared.

For an education on the wide range of bodies and body parts available to we humans, check out the difference in volume between B-cup and E-cup breasts on a woman with a 36" chest. It's similar to the difference between the 9x7" porn star and the 6x5" average Joe. And if you look at the percentage of women who wear an E-cup bra you'll find it's similar to the percentage of men with a 33ci penis. It all fits in a bell curve. Cool!

Speaking of bell curves and percentiles, I would love to see a REAL objective data set on a large population of males, just to see how it really works out. If I had to guess, I would say that somewhere between 75-95% of all men land within the yellow OR green area. Everyone else would be considered 'outliers'. Funny thing, based on my "informal" research I have found talking to girls that I slept with that I must be in the top 90% range, even though I fall right in the middle to high side of the green. I dated a slutty size queen once that after 30 guys, she had only been with one bigger than me. Only a small handful of girls I had been with have ever had bigger. Seems strange to me because on this site (assuming everyone is honest) I would be considered well below average, lol.

Okay, I'm too tired right now to examine your methods so I'll leave that for another day.

But according to your chart I'm a solid Blue, pushed into the lower end of Purple on a good day. That isn't right.

(Either way, I'm satisfied with what I have, but entertained this thread out of curiousity. )

Whoops, sorry No Strings, I guess I wasn't clear on this point - I don't expect anyone to use my formula to calculate their exact volume. I already did it for you. Just use the color coded chart that I attached in the second post.